The Colibri Page Builder plugin for WordPress suffers from a stored cross-site scripting vulnerability (CWE-79) due to improper neutralization of input during web page generation. Specifically, the colibri_newsletter shortcode does not adequately sanitize or escape user-supplied attributes, allowing authenticated users with contributor-level access or higher to inject arbitrary JavaScript code. This code executes in the context of any user who views the compromised page, potentially leading to session hijacking or other script-based attacks. The vulnerability affects all versions up to and including 1.0.334. The CVSS 3.1 base score is 6.4, reflecting network attack vector, low attack complexity, required privileges at the contributor level, no user interaction, and partial impact on confidentiality and integrity.

An attacker with contributor-level or higher privileges can inject persistent malicious scripts into pages via the vulnerable shortcode. These scripts execute in the browsers of users who visit the infected pages, potentially compromising user sessions or data confidentiality and integrity. There is no impact on availability. The vulnerability does not require user interaction to trigger once the malicious content is injected.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict contributor-level access to trusted users only and consider disabling or removing the colibri_newsletter shortcode if feasible to reduce exposure.